From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDD92CE7A89 for ; Sat, 23 Sep 2023 20:58:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229456AbjIWU6x (ORCPT ); Sat, 23 Sep 2023 16:58:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229606AbjIWU6v (ORCPT ); Sat, 23 Sep 2023 16:58:51 -0400 Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AF7F11B; Sat, 23 Sep 2023 13:58:45 -0700 (PDT) Received: by mail-pf1-f181.google.com with SMTP id d2e1a72fcca58-690b7cb71aeso3210625b3a.0; Sat, 23 Sep 2023 13:58:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695502725; x=1696107525; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=+JQqm/IVrcsmgTAsdrlxoxSmuKKq2qQmGkyMVhE/DVg=; b=UGIg9F5slJfMRHCYX1pX5KQXdFa7no/Q9AyUjB1ERYfdPPPrUsMqaZqqySv19y474U SDvpvFI1LzMnrai+cbvuhFx0dcFK54Djgn2BRQ+rN9qqBYQk6wr7hzpWXOQ3syue9+Bs c45BpRjDaUshOOxtTpuuMO38jVqMd2VVIF/Rl5CnxHnZrwxTIvNWrLdod4mjWpT2S6/U tnI1sk5fSOodft/sPcQdvm9ImqIFzSI9kva0OWTR4V++7S9R9iaPzOYjTy7KjIEBwMv1 vlAbnfpMMXOMSl9Xp0n2x2NcIwoi66fCwv+7foAWoKv3F0VhNDPAXN8ZkYlbO62Ek1Ii W85w== X-Gm-Message-State: AOJu0YxsaDqXcNcFYlFEf1D59FHzCYQaWsWI4YqXrkDUXZBrkseajc80 r1M6FKvJL7tOIFredXBSQkU= X-Google-Smtp-Source: AGHT+IGLsgmqCfwszNPSgEZ54z3W+6vxUJ/kWD5yJUxDrK/C3A/n6GNmdW50LzQ5Yrx+aO9ZIIeQaQ== X-Received: by 2002:a05:6a00:32cc:b0:68f:c8b4:1a2b with SMTP id cl12-20020a056a0032cc00b0068fc8b41a2bmr9179930pfb.17.1695502724656; Sat, 23 Sep 2023 13:58:44 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([20.69.120.36]) by smtp.gmail.com with ESMTPSA id z22-20020aa791d6000000b0068a0c403636sm5309505pfa.192.2023.09.23.13.58.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 23 Sep 2023 13:58:43 -0700 (PDT) Date: Sat, 23 Sep 2023 20:58:00 +0000 From: Wei Liu To: Greg KH Cc: Nuno Das Neves , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, patches@lists.linux.dev, mikelley@microsoft.com, kys@microsoft.com, wei.liu@kernel.org, haiyangz@microsoft.com, decui@microsoft.com, apais@linux.microsoft.com, Tianyu.Lan@microsoft.com, ssengar@linux.microsoft.com, mukeshrathor@microsoft.com, stanislav.kinsburskiy@gmail.com, jinankjain@linux.microsoft.com, vkuznets@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, will@kernel.org, catalin.marinas@arm.com Subject: Re: [PATCH v3 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V Message-ID: References: <1695407915-12216-1-git-send-email-nunodasneves@linux.microsoft.com> <1695407915-12216-16-git-send-email-nunodasneves@linux.microsoft.com> <2023092318-starter-pointing-9388@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2023092318-starter-pointing-9388@gregkh> Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org Greg, thank you for looking at the code. On Sat, Sep 23, 2023 at 09:56:13AM +0200, Greg KH wrote: > On Fri, Sep 22, 2023 at 11:38:35AM -0700, Nuno Das Neves wrote: > > +static int __init mshv_vtl_init(void) > > +{ > > + int ret; > > + > > + tasklet_init(&msg_dpc, mshv_vtl_sint_on_msg_dpc, 0); > > + init_waitqueue_head(&fd_wait_queue); > > + > > + if (mshv_vtl_get_vsm_regs()) { > > + pr_emerg("%s: Unable to get VSM capabilities !!\n", __func__); > > + BUG(); > > + } > > > So you crash the whole kernel if someone loads this module on a non-mshv > system? > > That seems quite excessive and hostile :( > I agree this can be more lenient. It should be safe to just return an error code (ENODEV) and let user space decide the next action. Saurabh, let me know what you think. Thanks, Wei. > Or am I somehow reading this incorrectly? > > thanks, > > greg k-h > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C5DF4CE7A89 for ; Sat, 23 Sep 2023 20:59:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZvnfDG/SNxVBECyuAewRfRQCAcob1KLkzZkrdRdiCmA=; b=kbeYuoOO8Es3Ok el9YGX6ozJ6ovII46azkRhSZ7rThlN4fi5/NP7GvJRTtR4RMbjpwZSEEsbkMWIcZfNC7jtDDauHec 9kfZzaKwSlezn6g2sA/xKEx5Pl/oS3CxRloIdAPJvfANebPELkV0/CAaIsO/MjD/ajV0/ZdelW39a 1molN+YjrvR3QxhucB7ki6bMRTvURPbSwM7N0GZgU5H8v5wMuAhYzG3Kt/EtcFcIsyfxuGAUqDvkm iIgzHFwXi5MSaQ7kzdKnzDfzTRgLetKHIqaGT0T/Vnjxjhmnn/OKzeerJX9lM1F5cwtcJ8g0uOeKE xvKsV5p6JOLbsT6Sy/3g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qk9iK-00BRi2-0H; Sat, 23 Sep 2023 20:58:56 +0000 Received: from mail-pf1-f175.google.com ([209.85.210.175]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qk9iH-00BRh5-0w for linux-arm-kernel@lists.infradead.org; Sat, 23 Sep 2023 20:58:54 +0000 Received: by mail-pf1-f175.google.com with SMTP id d2e1a72fcca58-690d2441b95so3198561b3a.1 for ; Sat, 23 Sep 2023 13:58:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695502725; x=1696107525; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=+JQqm/IVrcsmgTAsdrlxoxSmuKKq2qQmGkyMVhE/DVg=; b=eFKrB2OIISSQNlfJdaco429OIv/GekvAESb1/9Ldfghvxaxvn0st9XcAFp7aCYvM4k 7s7Jkm8CgFXVmUGJl+qHSRO7ZHu+dCh0JiPuBgw8biLjU5gTU8WLaK7cbaU2N/fN14os DFq7I3ASsWBJnfP5e5iXfQYM9x2fnNwAVvoFH+rQpRx3DH3dJQ9EjPwfCSTVzdhSVu3P o0Xu0Qlmq9Jc9c9RG83b/kv3DgzmzMZ+z0ZiCqrLNhOdVaoAZcU48fDWJKifHOkmFLya J3b88pYJYrmtxb2TmMFnacH8tL3qdWHykUe1Lw0fnpp+EP2HLjiq8DLG8MPZdaYW0IEz 4DTA== X-Gm-Message-State: AOJu0YwbDHfYe49VGbx8WNPgTefurp7mTk2qmFzFQyvBJDq1UAnULqZu mfiokgLMhi9yHigTltMD42g= X-Google-Smtp-Source: AGHT+IGLsgmqCfwszNPSgEZ54z3W+6vxUJ/kWD5yJUxDrK/C3A/n6GNmdW50LzQ5Yrx+aO9ZIIeQaQ== X-Received: by 2002:a05:6a00:32cc:b0:68f:c8b4:1a2b with SMTP id cl12-20020a056a0032cc00b0068fc8b41a2bmr9179930pfb.17.1695502724656; Sat, 23 Sep 2023 13:58:44 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([20.69.120.36]) by smtp.gmail.com with ESMTPSA id z22-20020aa791d6000000b0068a0c403636sm5309505pfa.192.2023.09.23.13.58.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 23 Sep 2023 13:58:43 -0700 (PDT) Date: Sat, 23 Sep 2023 20:58:00 +0000 From: Wei Liu To: Greg KH Cc: Nuno Das Neves , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, patches@lists.linux.dev, mikelley@microsoft.com, kys@microsoft.com, wei.liu@kernel.org, haiyangz@microsoft.com, decui@microsoft.com, apais@linux.microsoft.com, Tianyu.Lan@microsoft.com, ssengar@linux.microsoft.com, mukeshrathor@microsoft.com, stanislav.kinsburskiy@gmail.com, jinankjain@linux.microsoft.com, vkuznets@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, will@kernel.org, catalin.marinas@arm.com Subject: Re: [PATCH v3 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V Message-ID: References: <1695407915-12216-1-git-send-email-nunodasneves@linux.microsoft.com> <1695407915-12216-16-git-send-email-nunodasneves@linux.microsoft.com> <2023092318-starter-pointing-9388@gregkh> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <2023092318-starter-pointing-9388@gregkh> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230923_135853_337114_3E0CBAC7 X-CRM114-Status: GOOD ( 15.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Greg, thank you for looking at the code. On Sat, Sep 23, 2023 at 09:56:13AM +0200, Greg KH wrote: > On Fri, Sep 22, 2023 at 11:38:35AM -0700, Nuno Das Neves wrote: > > +static int __init mshv_vtl_init(void) > > +{ > > + int ret; > > + > > + tasklet_init(&msg_dpc, mshv_vtl_sint_on_msg_dpc, 0); > > + init_waitqueue_head(&fd_wait_queue); > > + > > + if (mshv_vtl_get_vsm_regs()) { > > + pr_emerg("%s: Unable to get VSM capabilities !!\n", __func__); > > + BUG(); > > + } > > > So you crash the whole kernel if someone loads this module on a non-mshv > system? > > That seems quite excessive and hostile :( > I agree this can be more lenient. It should be safe to just return an error code (ENODEV) and let user space decide the next action. Saurabh, let me know what you think. Thanks, Wei. > Or am I somehow reading this incorrectly? > > thanks, > > greg k-h > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel